LEDs

LEDs (light-emitting diodes) are semi-conductors that convert electricity into light. Once used
just as indicator lights for electronics, LEDs have evolved into a major lighting technology
that may change the future of general illumination. LEDs are highly regarded for their long
life, energy efficiency, non-toxicity, durability, and flexibility. Yet as a fairly new and
rapidly changing lighting technology, much research is still needed in order to fully realize
the energy and cost savings potential of LEDs.

The Solid-State
Lighting Program at the LRC conducts necessary research and educational programs to enhance
this technology, overcome barriers to effective use, and help it to gain acceptance for general
illumination purposes.

LED Residential Under-cabinet Luminaires - NLPIP compared four LED linear under-cabinet luminaires with four traditional models in order to determine if the LEDs improved uniformity, color, illuminance, and efficacy.

ASSIST recommends: Parking Lot Lighting - An alternative metric for evaluating parking lot luminaires based upon its application efficacy. An online calculator estimates performance based upon this metric.

Lighting Education Online is an interactive, Internet-based education program for building, design, and facility management professionals who want to learn more about light and lighting. Available courses include:

The LED Lighting Institute is a three-day, hands-on workshop for people who want to learn more about this quickly evolving lighting technology in a small-class setting.

Projects

Dimming Behaviors of LED Replacement Lamps - LRC researchers investigated the dimming performance of commercially
available LED replacement lamps and the performance variations among
different residential dimmers.

Accelerated Life-test Method for LED Drivers - The LRC conducted a study to understand what factors influence the failure modes of standalone LED drivers, and to develop an accelerated test method to predict the useful life of an LED driver.

Lighting Supermarket Freezers with LEDs - A field study investigating the use of white LED lighting inside supermarket freezers, including energy comparisons with fluorescent, sales analyses, and shopper preferences.

Innovative Lighting Solutions for Senior Care Facilities - A demonstration showing how innovative lighting designs and advanced technologies, including LEDs, photosensors and occupancy sensors, can help seniors in long-term care facilities maintain independence and be more comfortable.

Characterizing the Thermal Resistance Coefficient of LEDs - The accuracy of measuring LED junction temperature—a strong predictor of LED performance—depends upon the value of the LED's thermal resistance coefficient. This study explored how thermal resistance changes with different parameters.

Electronic Walls and Ceilings Offer Adaptable Solid-State Lighting - The LRC and ASSIST are developing a flexible interior infrastructure that will integrate solid-state lighting with other building materials and systems. Such an infrastructure would allow for rapid reconfigurations of built-in lighting, making it as easy to redesign lighting.